I'm guessing maybe she meant a general letter written up by a doctor outlining the effects those shoes may have on students with epilepsy, seizure disorders, migraines etc, not an actual letter from Jane Doe's doctor stating that the sneakers may be harmful to her personally.
I don't see that as any different from the letters distributed during the H1N1 scare, informing students/parents of the risks of coming to school sick, or not washing your hands, or covering your mouth etc. Or the general letters sent home when a child in the class has lice. No HIPPA laws are violated tehre, just general info that makes it pretty obvious someone has been effected (or infected) and how to prevent it happening again.
thank you that I what I meant...